A Practical Guide to Biomechanics

We can often go down the long, and often winding, road of sports supplementation and how that can help you in improving your performance in the iron paradise. However, what are some other ways you can improve your performance? Biomechanics is a part of your life. In the sports science world, kinesiology is the science focussed on the study of motion. It involves diverse fields such as Sports Sociology, Motor Learning, and Biomechanics. Biomechanics contributes to the basic understanding of human moment possibilities and its constraints, by applying laws of mechanics to the human body.

In recent years, Physical Education has evolved from physical fitness and training to incorporating kinesiology and biomechanics. To every physical education enthusiast, a working knowledge of biomechanics principles is crucial to achieve two goals:
a) Improving your performance by taking mechanical advantage of the body
b) Ensuring safety by use of kinetics and kinematics to reduce forces acting on the body

Biomechanics is a field of study and athletics is all about performance in the field. Biomechanics is the subject at uni which generally gives sports science students headaches. Sports Scientists and Exercise Physiologists learn biomechanics in great detail as one avenue to maximise human performance. These 10 guiding principles of biomechanics help in conveying the message.

The Ten Guiding Principles of Biomechanics

1. The Principle of Force

That the force guides every motion is known to all. Everything around us occurs because of force. Hence, force can either be negative (say by causing an injury) or positive. Like being the prime factor behind crossing the line.

2. The Principle of Linked Segment

The simplest model, by which a human body could be described, would be that of stick joined at frictionless hinges. Muscles forces cause the sticks to rotate around joints and manage their speed. These segments have a distal end and proximal ends, with distal ends pointing away from the body. Our fingers can be thought of as distal ends. Muscles vary the speed at distal ends and as a result, the force at the distal end varies.

3. The Principle of Stretch Shorten cycle

If a muscle is stretched before it is shortened, it results in more force. This is essentially a cycle which begins at wind-up. So if you think of the action you go through when you’re throwing a ball and the difference in speed between throwing a baseball versus when you throw a ball to a young child (with a straightened arm). Hence, instead of emphasizing on windup, ideal position can lead to better performance.

4. The Principle of Impulse-Causing Momentum

Impulse, the product of force and time interval, causes a change in momentum and this change is in direction of the force. If the body’s direction of motion or the speed is not desired, then its momentum needs improvement. This problem could be arising due to the wrong application of muscle, and it may originate from the segment itself, not just the position.

5. The Principle of Continuity of Joint Force

Ideally, the segment motion should radiate outwards, starting from biggest to the smaller distal segment. If the timing of this outflow is smooth, then the applied impulse magnifies. On another hand, erroneous timing causes a jerk and negative impulse, slowing down the body.

6. The Principle of Summing Joint Force

The total applied force in distal parts is the sum of forces from all the joints. Hence to maximize the impulse, all the contributable joints should participate together to achieve better efficiency.

7. The Principle of Impulse Direction

It is the simplest application of the third law of motion. To have a change in momentum, apply impulse in that direction. To walk forward, push ground backward, to swim forward, push river water backward.

8. The Principle of Rotational Motion

A force acting on a body produces torque along the axis of rotation. The magnitude of this torque determines the change in angular momentum. By proper alignments of sections, this torque can be magnified to achieve greater rotational momentum.

9. Manipulation of the Moment Of Inertia

In absence of force, angular momentum stays constant. When we are in the air no force, except gravity, acts on us. However, if we change the shape of our body, we can increase or decrease our moments of Inertia. Thereby changing our angular velocity. However, this requires significant upper and lower body strength.

10. Stress-Strain Principle

Stress is the distribution of load over a tissue while strain is the resulting deformation of that tissue. Strain can boost tissue strength if enough time is provided to adapt. However, in absence of time, strain can damage the tissue. Hence, rest between physical activity sessions is necessary for a prolonged performance.

The Bottom Line

Biomechanics, as a field of study, has evolved in a diverse field. Biomechanists devise safe lifting techniques, your sports and gym equipment, and correct movements to maximise human performance. While above-described principles may not seem directly applicable to you, they might give you something to think about when you’re at the gym wondering how to lift heavier, jump higher or run faster. Understanding these principles will not only minimize the chances of injury but also maximize your performance.